The present invention relates to a hinge for preventing injuries due to crushing, especially in doors or windows, comprising a first hinge leaf for connection to the door or window leaf, a second hinge leaf for connection to the door or window frame and a swivel joint connecting the first and second hinge leaves to each other.
Such hinges are known from U.S. Pat. No. 2,883,699 and the present applicant's own Ser. No.-166, 099. The former teaches a hinge where the hinge leaf which is secured to the door is equipped with an extra swivel joint. If a finger or the like comes between the door leaf and the door jamb or frame, the hinge leaf will "break" around this extra swivel joint. The distance between this extra swivel joint and the true swivel joint of the hinge is such that there is sufficient room for, e.g., a finger. To prevent the hinge from breaking around the extra swivel joint when the door is closed normally, i.e., when there is no foreign object between the door leaf and the door jamb, the extra swivel joint is equipped with a spring which causes the hinge leaf to be held flat. The spring must be of a certain strength if this is to be achieved. This means that the foreign object, e.g., the finger of a child, must overcome this spring force before the hinge leaf is "broken" about the extra swivel joint. Certainly, these forces exerted on the finger of child would not be of the same magnitude as with a door equipped with a conventional hinge. However, they would exert a disagreeable pressure on the finger. At worst, if a small child is involved, injury may also be sustained.
In addition, the extra swivel joint is relatively complex, and if the spring were to be damaged, the hinge would not function properly, and it would be difficult to close the door.
The applicant's own Ser. No.-166,099 teaches a very much better hinge structure. Here, two outer hinge leaves are fixedly connected to the frame and the door leaf respectively, between which outer hinge leaves there is pivotally connected an intermediate hinge leaf. The intermediate hinge leaf is connected to opposite edges of the outer hinge leaves. Only the lower hinge of the door is of this type, whilst the upper door hinge is of a conventional type. This means that normally the weight of the door will hold the intermediate hinge leaf in abutment with the outer hinge leaf which is secured to the door. If a foreign object comes between the door frame and the door leaf, the normally closed angle between the intermediate hinge leaf and the outer hinge leaf secured to the door will open.
However, it has been found that when a foreign object comes between the door leaf and the door frame, this hinge will easily bend. Moreover, the normally closed angle between the intermediate hinge leaf and the outer hinge leaf secured to the door could easily open, even when the door is in the open position.